As an alternative to performing more invasive procedures, many physicians are using minimally invasive devices to examine and/or treat internal body tissues of patients. Examples of such minimally invasive devices include endoscopes and catheters. Typically, such devices include an elongated shaft that is inserted into the patient and a mechanism for producing images from the distal end of the device. Such mechanisms include fiber optic imaging guides that transmit light to a proximally located camera. Alternatively, the devices may include an image sensor at the distal tip that produces electronic signals that are used to produce video images of the internal body cavity. To reduce the costs associated with repeated disinfection and repair of such devices, some endoscopes and catheters may be designed to be single-use. Examples of single-use endoscope designs are described in U.S. patent application Ser. Nos. 10/811,781, and 10/196,007, assigned to Boston Scientific Scimed, Inc., the assignee of the present application. These applications are herein incorporated by reference.
One factor that has limited the ability to make commercially feasible single-use endoscopes or imaging catheters is the cost of the required imaging optics. To make a practical single-use device, such optics should provide images that are as good as or better than those obtained with conventional re-usable devices. In addition, these optics should be inexpensive such that the cost of the overall device allows it to be used once and thrown away. Accordingly, improved optical assemblies, endoscopes, and medical imaging devices are needed.